Glucoamylases (glucan 1,4-α-glucohydrolases, EC 3.2.1.3) are starch hydrolyzing exo-acting carbohydrases, which catalyze the removal of successive glucose units from the non-reducing ends of starch or related oligo and polysaccharide molecules. Glucoamylases can hydrolyze both the linear and branched glucosidic linkages of starch (e.g., amylose and amylopectin).
Glucoamylases are produced by numerous strains of bacteria, fungi, and plants. Certain fungal glucoamylases are produced and secreted, such as from strains of Aspergillus. 
Other fungi, such as Monascus, have a long tradition in the preparation of fermented foods. For example, Monascus strains have been used for the fabrication of tofu in China and Japan. Historically, the fungus has been used primarily as a food additive. The organism is typically grown on rice, dried and milled, and added as ‘RotReis’ to meat products. Various food ingredients are also produced by species of Monascus. For example, pigments used in the household and in industry are produced from Monascus purpureus. 
Monascus is also used as an alternative medicine. For example, red yeast rice, which is rice infected with Monascus purpureus, is a natural food product that is understood to lower blood cholesterol. The active component, an HMG-CoA reductase inhibitor, lowers overall blood cholesterol as well as blood LDL cholesterol levels and may even reverse coronary artery disease. The product produced by Monascus purpureus has been called Monacolin K, or Cholestin (Pharmanex).
Monascus fermentation extract has also been claimed to act as an anti-cancer drug, as disclosed in U.S. Patent Application Publication No. 2004/0081663 A1. As disclosed in U.S. Pat. No. 6,613,365, use of Monascus kaoliang in animal feed is described.
JP2007097462 describes the cultivation of Monascus purpureus to produce liquid koji (for use in making a fermented food/beverage), which comprises detectable glucoamylase activity.
U.S. Pat. No. 4,870,014 describes the cloning of thermolabile glucoamylase from S. diastaticus and its expression in S. cerevisiae for use during the fermentation step of brewing. U.S. Pat. No. 4,318,989 describes methods for producing glucoamylase (glucoamylaseS and exo-pullulanase) from Cladosporium resinae for use during the fermentation step of brewing.
It is well acknowledged that glucoamylases are very important commercial enzymes, and have been used in a wide variety of applications that require the hydrolysis of starch (e.g., for producing glucose and other monosaccharides from starch). However, the bulk of commercial glucoamylase is produced by fungal strains of Aspergillus niger. 
A significant portion of the secreted protein product from these fungal sources is alpha amylase, which is an undesirable product when the goal is the isolation of glucoamylase. The presence of these unwanted enzymes and other background proteinaceous products slow down the process of isolating the desired glucoamylase, and inevitably decreases the overall yield per batch. Therefore, a need still exists for producing and isolating a high quality yield of glucoamylase while reducing unwanted products in the production process.
The purification and properties of two forms of glucoamylase from Monascus kaoling were disclosed ((Iizuka et al., (1977), J. Gen. Appl. Microbiol., 23(5): 217-230; Iizuka et al., (1978), J. Gen. Appl. Microbiol., 24: 185-192). Both glucoamylases were stated to be stable at up to 50° C., but at temperature around 60° C.-70° C. glucoamylase activities dropped sharply. The sequences of the two forms of glucoamylases were not disclosed in this article or in later publications.
The use of glucoamylases in the hydrolysis of starch derived carbohydrate has increasing importance in the brewing industry, particularly for the production of highly attenuated (sometimes referred to as low calorie) beers. For reasons relating to product stability and legislation it is important that the added enzymatic activity is removed/inactivated in the final beer. Unfortunately this requirement is difficult to fulfill due to the thermostability of the enzymes, when the glucoamylase is derived from the usual source Aspergillus spp., such as A. niger and A. awamori; Humicola spp.; Talaromyces spp., such as T. emersonii; Athelia spp., such as A. rolfsii; Penicillium spp., such as P. chrysogenum, for example, and the enzyme is added into the fermenting vessel (FV) in the brewing process.
Although the addition of glucoamylase to the mashing vessel, or at any stage prior to wort boiling, may avoid this problem, this introduces other practical difficulties. U.S. Pat. No. 4,666,718 describes a brewing process employing a reactor comprising the brewing enzyme glucoamylase immobilised on a solid support, whereby the enzyme can be recovered from the product. U.S. Pat. No. 5,422,267A describes a brewing process employing genetically engineered yeast expressing a recombinant glucoamylase, but where the enzyme is secreted by the yeast.
Therefore, a need still exists for polypeptides for example in the form of a composition having glucoamylase activity that can be added to any stage of a conventional process for preparing a fermented beverage such as beer using conventional equipment and whose activity can safely be removed from the final product.
It would be especially efficient to add polypeptides having glucoamylase activity for example in the form of a composition into a fermentation vessel (FV) used in preparing a fermented beverage. The benefits are for example lower enzyme doses, increased starch conversion to fermentable carbohydrate (for example through low isomaltose production) and reduced yeast stress. The reason why this approach is not commonly used is that active enzymes then may be present in the final product, which is undesirable as described above. The commercially available glucoamylases are in general thermostable and the energy applied during pasteurisation of a fermented beverage is not sufficient to inactivate the enzymes. Thus, a further need exist for a thermolabile glucoamylase that may be inactivated by pasteurisation after fermentation.